/ Dictionary / Index S square number: Meaning and Definition of Find definitions for: square' num'ber Pronunciation: [key] a number that is the square of another integer, as 1 of 1, 4 of 2, 9 of 3, etc. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. square millimeter square of opposition Related Content Daily Word Quiz: mamba Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language